Heart mRNA profiles of TAC 8-weeks wild type (WT) and miR-27b-3p knockout mice

Aim: The heart undergoes pathological remodelling under increased stress and neuronal imbalance. MicroRNAs (miRNAs) are involved in post-transcriptional regulation of genes in cardiac physiology and pathology. However, the mechanisms underlying miRNA-mediated regulation of pathological cardiac remodelling remain to be studied. This study aims to explore the function of endogenous microRNA-27b-3p (miR-27b-3p) in pathological cardiac remodelling. Methods and results: We found that miR-27b-3p expression was elevated in heart of patients with cardiac hypertrophy and in transverse aortic constriction (TAC)-induced cardiac hypertrophy mouse model. MiR-27b-3p-knockout mice showed significantly attenuated cardiac hypertrophy, fibrosis, and inflammation induced by two independent pathological cardiac hypertrophy models, TAC and Angiotensin II (Ang II) perfusion. Transcriptome sequencing analysis revealed that miR-27b-3p deletion significantly downregulated TAC-induced cardiac hypertrophy, fibrosis, and inflammatory genes. We identified fibroblast growth factor 1 (FGF1) as a novel miR-27b-3p target gene in the heart, which was upregulated in miR-27b-3p-null mice. Conclusions: Our study has demonstrated that miR-27b-3p induces pathological cardiac remodelling and suggests that inhibition of endogenous miR-27b-3p or administration of FGF1 might have the potential to suppress cardiac remodelling in a clinical setting. heart mRNA profiles of TAC 8-weeks wild type (WT) and miR-27b-3p knockout mice